Loud speaker



May 5, 1931. J. T. CORRIGAN ,803,892

LOUD SPEAKER Filed April 12, 1927 gnueufoz Jam 2: (brag an $51 OMJMPatented May 5, 1931 JAMES T. GORR-IGAN, OF WASHINGTON, DISTRICT OFCOLUMBIA LOUD SPEAKER Application filed April 12,

My invention relates to new and useful improvements in sound reproducingdevices and more particularly to what is commonly known as a loudspeaker.

'5 One of the objects of the present invention is to produce a loudspeaker in which there is located an actuating unit, which in turneffects two or more diaphragms of difierent area and naturally of difierent frequencies, so

that both the low notes and the high notes may be faithfully reproduced.

Still another object of the invention is to produce a loud speakerhaving two difierent size diaphragms actuated by the one electrical unitand to so proportion the diaphragms that the reproducing will produce amusical note and its harmonic thereby adding timber or colour to thetone.

Still another object of the invention is to provide a reproducer or loudspeaker having two different size diaphragms actuated simultaneously bythe one electrical unit, the two diaphragms being connected to eachother and to the one unit, and to further provide two cylinders, one ofthe cylinders being secured to the smaller diaphragm and enclosed withina larger cylinder which in turn is connected with the larger of thediaphragms.

Still another object of the invention is to produce a loud speaker whichwill produce two separate pitches of the same musical notesimultaneously, the pitch variation of one being a harmonic of thevibrating frequency of the other cylinder.

Of course if the larger tube were not placed in vibration by the unit,the inner cylinderwhen in a state of vibration would cause the largerbody to vibrate in the same period, which is known as consonance.

However, by employing two diaphragms of different angularity and ofdifferent area actuated by the same unit and by having two cylinders onewithin the other, not only may the high and low notes be more faithfully45 reproduced, but the notes and their harmonies are producedsimultaneously, thus adding richness of tone or timber to thereproducer.

With the above and other objects in view,

60 the invention consists in certain new and 1927. Serial No. 183,083.

novel arrangements and combination of parts, as will be hereinafter morefully described and pointed out in the claims.

Referring now to the drawings showing the preferred embodiment,

Fig. 1 is a prospective of my new reproducer or loud speaking unit,

Fig. 2 is a longitudinal sectional view of the same, and

Fig. 3 is a sectional view of the two diaphragms slightly spaced apartfor the sake of clearness.

Referring now more particularly to the drawings, there is shown a baseor support 1, which may be of wood or metal as desired, while at one endthere is seen a vertical standard 2, to which there is secured the crossarm 3. As may be seen in Fig. 2, the standard 2 is slotted at its bottomas at l, and at its top as at 5, the standard being slightly enlarged atthese two places.

There will also be noted a cylinder 6 that is supported at its outer endby a small stud or post 7, while the inner end of the cylinder issupported in the slots 4L and 5 in the standard heretofore mentioned.

This cylinder is preferably composed of a soft paper, which has verylittle grain and may be procured in the open market and is especiallyadapted for the manufacture of diaphragms or cones of the loud speakingunits now in use.

In the present instance I have shown the cylinder having a lengthsubstantially twice its diameter and although the speaker as constructedby me has a length of a foot and a half, it may be made larger orsmaller if so desired.

Located within one end of this cylinder, is the diaphragm 8 which isprovided with the small flange or rim 9, and secured to the cylinder byglue or in any preferable manner. The diaphragm is conical in crosssection and has its apex provided with a small opening 10 for thereception of the arm 11 that extends from the electrical reproducingunit 12.

This diaphragm 8 is also preferably formed of paper such as is used forthe cylinder and is commonly used in the manufacture of cone speakers,although, if a metal diaphragm could be found of the right elasticity,it might equally well be used.

The electrical reproducing unit 12 of any Well known suitable type isfastened to the standard 2 and to the cross bars 3, while from bindingposts on this unit 12 there is fragmentarily shown a cord 13 that willbe connected to a radio set.

Now located within this outer cylinder 6 is the inner cylinder 14 alsoformed of paper, the area of this cylinder being two-thirds of that ofthe outer cylinder 6.

Fixedly secured to the inner end of this cylinder 14 is the paperdiaphragm 15, its area being wo-thirds of the area of the diaphragm 8 sothat its frequency vibration is substantially two-thirds of that of thelarger diaphragm. The frequency variation is therefore one-third of theouter which causes the harmonic frequency between the two diaphragms. twill be understood that by changing the relative size of the innercylinder and diapliragms, different ha monics might be produced whichdifferent harmonics might be desired under certain circumstances.

It will also be seen thatthe angularity of the larger diaphragm issubstantially half of the angle of the inner diaphragm, so that theapices may contact and the remainder of the diaphragms spaced so thatthey are both free to vibrate throughout substantially their entirearea.

A small button 16 is provided With the flange 17 and a further flange18, while the inner end of the button is enlarged so that the apices ofthe diaphragms may be clamped about the button and the rod 11 will passthrough the button and diaphragms and fasten to the button by the setscrew 19.

Therefore the vibrations produced in the electrical unit will betransferredthrough the rod 11 to the two diaphragms to'actuate' them inthe same manner that one is generally actuated.

The vibrations will be transmitted to the cylinders and the vibrationsfrom the inner cylinder will also assist in setting into vibration theouter cylinder, and due to the areas of the cylinders a rather largemass of air will be set in motion. Due tothe size of the largerdiaphragm and the cylinder, the larger cylinder will more faithfullyreproduce the deep notes while the smaller cylinder and the smallerdiaphragm will more faithfully reproduce the higher notes;

Due to the large ano small diaphragm-s therefore, both the high and thelow notes are more faithfully reproduced than where one 7 diaphragm isused alone, and furthermore by correctly proportioning the size of thecylin ders and diaphragms not only are the note or notes reproduced buttheir harmonics are more clearly brought out, which as heretoforementioned adds amplitude and timber or quality.

The intensity of the note depends of course on the extent of itsvibrations and by having the large and small diaphragms both to beactuated instantaneously the intensity is greater than where simply onediaphragm is used. The pitch from the one diaphragm will be differentfrom the pitch of the other, but they are arranged so that one willproduce the harmonic.

It will be understood that a further number of harmonics might beproduced by addfurther cylinders and further diaphragms of the properdimensions.

From the foregoing it will be seen that I have invented a loud speakerwhich Will more faithfully reproduce all the audio frequencies of themusical scale and furthermore I have been able to supply the depth orcolour to the reproduction; I can also more faithfully reproduce boththe high notes and low notes and also reproduce notes with round or deepquality which has heretofore -een missing in most of theloud'speakers'in resent day use.

It will be understood that many slight chan es might be made without inany Way departing from the spirit and scope of the invention.

fiaving thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A loud speaker comprising an actuating unit, supporting means forsaid unit, two diaphgramsphysically connected to a part of said unit,said diaphragms being of different areas and cylinders connected one toeach of said diaphragms and the connection being such that the diaphragmandcylindcr in each instance are substantially integral.

2. A loud speaker comprising a base, an actuating unit two cylinderssupported by said base and one within the other, vibratory diaphragmssecured respectively in one end of each of said cylinders and physicallyconnected with a portion of said actuating unit, the areas of the twodiaphragms being in such proportion that the notes and their harmonicsare simultaneously produced.

3. A loud speaker comprising two cylinders, one of which issubstantially two thirds of the area of the other, one-of said cylindersbeing enclosed within the other of said cyl"- inders, a vibratorydiaphragm fastened in an end of eachof's'aid cylinders, an actuatingunit physically connected to both of saiddiaphragms and the areas of therespective diaphragms and cylinders being such that the notes and theirfirst harmonic are simultaneously produced.

4. A sound reproducer comprising a base and two cylinders mountedthereon, one of said cylinders being substantially two-thirds in area ofthe other of said cylinders, a' vibratory conical diaphragm secured ineach of said cylinders and each diaphragm located at the inner end ofeach cylinder, said diaphragms contacting at their apices, an actuatingunit connected to said-diaphragms, the area of the smaller diaphra m andcylinder being substantially two-thir of the area of the largerdiaphragm and cylinder, whereby notes and their harmonics will besimultaneously reproduced.

5. A loud speaker comprising two cylinders formed of suitable vibratorymaterial, one of said cylinders being enclosed within the other and theone being substantially twothirds the area of the other, a conicaldiaphragm respectively secured in an end of each of said cylinders, thearea of the one diaphragm also being substantially two-thirds of thearea of the other, and actuating mechanism physically connected to bothof said diaphragms and clamping the said diaphragms tightly together attheir apices, the angularity of one diaphragm being substan tiallyone-half the angularity of the other diaphragm. H

6. A loud speaker comprising two cylinders of suitable vibratorymaterial, one enclosed within the other, a base supporting saidcylinders and a standard on said base and supporting an actuating unit,two diaphragms of different frequencies physically connected to saidactuating unit and to their respective cylinders whereby the low andhigh notes may be more faithfully reproduced and the vibrations of thediaphragms will be transferred to the said cylinders and whereby thefundamentals and harmonics will also be produced on the actuation of thesaid diaphragms.

7. A loud speaker comprising an actuating means, two cone-shapeddiaphragms of different frequencies physically connected to saidactuating unit, the magnitude of the angle of one diaphragm beingdifferent from the other and the area of the one diaphragm being alsodifferent from the other and cylinders secured to the said diaphragms,one cylinder being positioned within the other.

8. A loud speaker for reproducing notes of high and low frequencies andfor reproducing the primary and harmonics consisting of an actuatingunit, a cylinder and a diaphragm therein and a second cylinder anddiaphragm of substantially two-thirds the area of the first mentioneddiaphragm and cylinder, the said diaphragms being substantially conicalin shape and having their apices connected to each other and to the saidactuating unit the said diaphragms and cylinders being formed ofsuitable sound-reproducing vibratory material.

9. A reproducer comprising an actuating unit, a plurality of conicaldiaphragms of difl erent areas and angularities, a plurality of tubeseach of which is inherently fastened to one of said diaphragms, saiddiaphragms being physically connected together at their apices and tothe said actuating unit in order that all of the diaphragms and tubesmay vibrate simultaneously.

10. A reproducer comprising two tubular members of difierent diameters,each of said tubular members being closed at one end by a conicaldiaphragm, each of said diaphragms being of different angularity, anactuating unit, and each of said diaphragms being connected to eachother and the said actuating unit.

11. A reproducer comprising a tubular member inherently closed at oneend by a small cone, a similar tubular member of larger diameter andhaving a larger cone inherently closing the same, and one tube fittingwithin the other tube and cone, the said cones clamped together at theirapices, and an actuating unit rigidly secured also to the two conicalapices.

In testimony whereof I aflix my signature.

JAMES T. CORRIGAN.

